The Middle Miocene Carbonate Crash:Relationship to Neogene Changes inOcean Circulation and Global Climate
In this thesis a comprehensive data collection mainly from non-destructive XRF core scanner measurements and oxygen isotope data have been applied for reconstructing and interpreting paleoenvironmental changes in Neogene sediments of the South Atlantic. The obtained data document the geochemical reo...
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Universität Bremen
2003
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Online Access: | https://media.suub.uni-bremen.de/handle/elib/1948 https://nbn-resolving.org/urn:nbn:de:gbv:46-diss000007286 |
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ftsubbremen:oai:media.suub.uni-bremen.de:Publications/elib/1948 2023-05-15T13:42:30+02:00 The Middle Miocene Carbonate Crash:Relationship to Neogene Changes inOcean Circulation and Global Climate Der mittelmiozäne Karbonat-Zusammenbruch:Wechselwirkung mit globalen Zirkulations-und Klimaänderungen Westerhold, Thomas Wefer, Gerold Henrich, Rüdiger 2003-12-19 application/pdf https://media.suub.uni-bremen.de/handle/elib/1948 https://nbn-resolving.org/urn:nbn:de:gbv:46-diss000007286 eng eng Universität Bremen FB5 Geowissenschaften https://media.suub.uni-bremen.de/handle/elib/1948 urn:nbn:de:gbv:46-diss000007286 info:eu-repo/semantics/openAccess Miocene South Atlantic carbonate crash oxygen isotopes orbital tuning XRF scanner Mi-events 31 ddc:31 Dissertation doctoralThesis 2003 ftsubbremen 2022-11-09T07:09:42Z In this thesis a comprehensive data collection mainly from non-destructive XRF core scanner measurements and oxygen isotope data have been applied for reconstructing and interpreting paleoenvironmental changes in Neogene sediments of the South Atlantic. The obtained data document the geochemical reorganization in the world oceans across the middle to late Miocene transition (basin-to-basin fractionation) which mainly is contributed to the uplift of the Central American Seaway and expansion of the Antarctic ice-sheet. Detailed comparison of carbonate sedimentation patterns from different regions and different water depth clearly show that the carbonate crash events differ substantially in timing and magnitude. In addition, the congruent variability of shallow and deep water carbonate records contradict the assumed gradients between intermediate and deep-water masses as predicted by modeling studies. Furthermore, the present study suggests that interactions exist between the geochemical reorganization of the world oceans and climate events during the Neogene. For example, the close timing of aridification in South Africa and Patagonia, strengthening of the Antarctic Circumpolar Current, begin of Benguela upwelling, intensification of Southern Hemisphere winds and expansion of the Antarctic ice-sheet point to a common driving mechanism. The configuration of ocean gateways and sills (i.e. Central American Seaway, Greenland-Scotland Ridge) seem to play a key role in the observed changes in ocean chemistry. Other factors like the uplift of major orogenes (Andes, Himalayas) might have significant influence on the ocean geochemistry and therefore carbonate sedimentation pattern. Doctoral or Postdoctoral Thesis Antarc* Antarctic Greenland Greenland-Scotland Ridge Ice Sheet Media SuUB Bremen (Staats- und Universitätsbibliothek Bremen) Antarctic Greenland Patagonia The Antarctic |
institution |
Open Polar |
collection |
Media SuUB Bremen (Staats- und Universitätsbibliothek Bremen) |
op_collection_id |
ftsubbremen |
language |
English |
topic |
Miocene South Atlantic carbonate crash oxygen isotopes orbital tuning XRF scanner Mi-events 31 ddc:31 |
spellingShingle |
Miocene South Atlantic carbonate crash oxygen isotopes orbital tuning XRF scanner Mi-events 31 ddc:31 Westerhold, Thomas The Middle Miocene Carbonate Crash:Relationship to Neogene Changes inOcean Circulation and Global Climate |
topic_facet |
Miocene South Atlantic carbonate crash oxygen isotopes orbital tuning XRF scanner Mi-events 31 ddc:31 |
description |
In this thesis a comprehensive data collection mainly from non-destructive XRF core scanner measurements and oxygen isotope data have been applied for reconstructing and interpreting paleoenvironmental changes in Neogene sediments of the South Atlantic. The obtained data document the geochemical reorganization in the world oceans across the middle to late Miocene transition (basin-to-basin fractionation) which mainly is contributed to the uplift of the Central American Seaway and expansion of the Antarctic ice-sheet. Detailed comparison of carbonate sedimentation patterns from different regions and different water depth clearly show that the carbonate crash events differ substantially in timing and magnitude. In addition, the congruent variability of shallow and deep water carbonate records contradict the assumed gradients between intermediate and deep-water masses as predicted by modeling studies. Furthermore, the present study suggests that interactions exist between the geochemical reorganization of the world oceans and climate events during the Neogene. For example, the close timing of aridification in South Africa and Patagonia, strengthening of the Antarctic Circumpolar Current, begin of Benguela upwelling, intensification of Southern Hemisphere winds and expansion of the Antarctic ice-sheet point to a common driving mechanism. The configuration of ocean gateways and sills (i.e. Central American Seaway, Greenland-Scotland Ridge) seem to play a key role in the observed changes in ocean chemistry. Other factors like the uplift of major orogenes (Andes, Himalayas) might have significant influence on the ocean geochemistry and therefore carbonate sedimentation pattern. |
author2 |
Wefer, Gerold Henrich, Rüdiger |
format |
Doctoral or Postdoctoral Thesis |
author |
Westerhold, Thomas |
author_facet |
Westerhold, Thomas |
author_sort |
Westerhold, Thomas |
title |
The Middle Miocene Carbonate Crash:Relationship to Neogene Changes inOcean Circulation and Global Climate |
title_short |
The Middle Miocene Carbonate Crash:Relationship to Neogene Changes inOcean Circulation and Global Climate |
title_full |
The Middle Miocene Carbonate Crash:Relationship to Neogene Changes inOcean Circulation and Global Climate |
title_fullStr |
The Middle Miocene Carbonate Crash:Relationship to Neogene Changes inOcean Circulation and Global Climate |
title_full_unstemmed |
The Middle Miocene Carbonate Crash:Relationship to Neogene Changes inOcean Circulation and Global Climate |
title_sort |
middle miocene carbonate crash:relationship to neogene changes inocean circulation and global climate |
publisher |
Universität Bremen |
publishDate |
2003 |
url |
https://media.suub.uni-bremen.de/handle/elib/1948 https://nbn-resolving.org/urn:nbn:de:gbv:46-diss000007286 |
geographic |
Antarctic Greenland Patagonia The Antarctic |
geographic_facet |
Antarctic Greenland Patagonia The Antarctic |
genre |
Antarc* Antarctic Greenland Greenland-Scotland Ridge Ice Sheet |
genre_facet |
Antarc* Antarctic Greenland Greenland-Scotland Ridge Ice Sheet |
op_relation |
https://media.suub.uni-bremen.de/handle/elib/1948 urn:nbn:de:gbv:46-diss000007286 |
op_rights |
info:eu-repo/semantics/openAccess |
_version_ |
1766168654671511552 |